These are true and false questions and I want to make sure that I got them right.
1. A water molecule is held together by two single polar covalent bonds. False
2. Because oxygen has a greater electronegativity than hydrogen, water molecules are polar with two partial negative charges near the oxygen atom and one partial positive charge near each hydrogen atom. False
3. Atoms differ in their affinity for neutrons, a property called electronegativity. False
4. In general, electronegativity increases from left to right across each row of the periodic table and also increases down each column. False
5. In a nonpolar covalent bond there is an equal sharing of electrons between two atoms while polar covalent bonds involve an unequal sharing of electrons. True
6. A single molecule of oxygen (O2) is held together by two double nonpolar covalent bonds. True
7. A covalent bond is formed when two atoms share one or more pairs of electrons. True
8. Polar molecules are electrically neutral but the distribution of charge within the molecule is not uniform. True
9. Although C and H differ slightly in electronegativity, this small difference is negligible, and C–H bonds are considered polar. False
10. Of the 4 most common elements found in living organisms, nitrogen has the highest electronegativity and, therefore, the greatest affinity for electrons. False
11. A slightly positive hydrogen atom on one water molecule can attract the slightly negative oxygen atom on a different water molecule, leading to the formation of a hydrogen bond. False